Shane's World Right Arrow SpeciesRight Arrow Ancistrus 101, Part 1 • The Basics

Article © Shane Linder, uploaded January 01, 2002.

An introduction to the bushy nose plecos of the genus Ancistrus
Erected by Kner in 1854, the genus Ancistrus, at the end of 2005, encompassed 59 valid species, making it the largest genus of the tribe Ancistrini. Ancistrus are readily distinguishable from all other loricariids by the presence of soft tentacles on their snout. Male Ancistrus, especially adult males in breeding condition, posses rather long tentacles along the snout margin and one, or more, rows of well developed tentacles on top of the snout. Depending on the species involved, the tentacles may be simple or branched. Females and juveniles usually posses only a simple row of tentacles along the snout margin.

As a genus, Ancistrus do not appear to show a preference to any distinct environment. In fact, Ancistrus species can be encountered from high Andean streams to lowland swamp environments and found in white, clear and black waters. As a general rule, species from white and clear waters range from light gray to medium brown and usually have a chaotic pattern of darker or lighter markings. Nearly all species encountered in blackwaters, however, are an over all dark brown to black with a pattern of small to medium sized white to yellow dots. Ancistrus are also capable of swallowing atmospheric air to aid their breathing in environments with a low oxygen content.

Why the bushy nose?
Sabaj et al. (1999) offered a very interesting, and plausible, reason why male Ancistrus develop their bushy noses. Sabaj and his fellow researchers observed that male Ancistrus often guard several broods of fry simultaneously. They also observed that female Ancistrus prefer to spawn with males that are already guarding a brood, possibly because these males have demonstrated that they are successful parents. Sabaj et al. thus theorized that males develop their tentacles to mimic the movements and appearance of larvae and thus "trick" females into believing that the male in question is already a successful parent and therefore a good choice as a mate.

A brief history
Ancistrus have long been popular aquarium fish, mainly for their world-renowned reputation as champion algae eaters, and have been present in the aquarium hobby since at least the early 1900s. The first documented spawning I could find appeared in the June 1975 issue of Tropical Fish Hobbyist magazine. The article "The Mating of Armor: Spawning A. triradiatus" was written by Craig Barzso and Sandy Caster. A photo of A. triradiatus appears with the article in Axelrod's "Breeding Aquarium Fishes: Book 5" (1978), but no photo credit appears, so it is not possible to know if Barzso and Caster supplied the photo or it was added later. Of interest, Axelrod states that he tried commercial reproduction of this fish but was unable to raise the fry to a saleable size. The next article I was able to locate was a 1979 article by the famous Hans-Joachim Franke of the then East Germany. Franke's photos, in "Breeding Aquarium Fishes: Book 6," show pictures of what we now call Ancistrus sp. 3 in the hobby. Franke did not offer a specific identity for his fish nor state where they were imported from. Possibly of historical interest, Franke's article was also the first mention I could find of feeding loricariids fresh vegetables.

Available species
Unfortunately, confusion has abounded (and continues to do so) with regards to identifying Ancistrus to the species level. The issue has been complicated by hobbyists attaching various, seemingly randomly chosen, scientific names to nearly every Ancistrusspecies imported. The most commonly abused scientific names being A. cirrhosus, A. temminicki, and A. dolichopterus. While the majority of wild caught Ancistrus species are difficult to impossible to identify, the situation has become slightly better over the years.

Ancistrus cf. cirrhosus, known on this side for a long time as Ancistrus sp.(3): This is the most commonly available Ancistrus species in the hobby and comes from captive bred stocks in Southeast Asia and Florida. Its specific identity remains unknown. There is a school of thought, partially because this species has not been identified, that it is some sort of hybrid. I personally doubt this based on Franke's 1979 photos, the fact that these fish always breed true without variation, and because Ancistrus sp. 3 in the Europe, Australia, and the U.S. all look like the same species. This species has been bred so long by commercial breeders that albino, long fin and even long finned albino forms have been fixed.

Ancistrus triradiatus (aka LDA 72): This species is the most commonly exported wild Ancistrus and is collected in great numbers around Villavicencio, Colombia for the aquarium trade. It is a piedmont species that can tolerate cooler temperatures (down to 72°F) with ease. It prefers faster flowing well oxygenated waters, but is extremely adaptable.

Ancistrus dolichopterus (aka L183): The true A. dolichopterus is available from Rio Negro shipments out of Manaus. It is an attractive blackwater Ancistrus that requires softer, warmer waters than the species above.

Information on several additional Ancistrus species can be found in the Cat-eLog

Diet and Feeding
All Ancistrus appear to be omnivores. However, this is a term that must be used with care. A fish that eats 90 percent animal proteins and 10 percent plants is an omnivore just as is a fish that eats 90 percent plants and 10 percent animal proteins. Ancistrus fall into the second group. That is, they need a large portion of plant matter in their diet and small portion of animal proteins. With the apparent exception of A. ranunculus and its close relatives, Ancistrus should be fed mainly on plant matter with occasional additions of animal proteins. Ancistrus that have been kept too long as "scavengers" feeding off the remnants of high protein dry, frozen, or live foods meant for their tankmates often develop blockages in their intestines that lead to bloat. This bloating can quickly become fatal if the fish is not placed back on a proper diet in time.

Their main diet should consist of fresh vegetables. Cucumber, green and yellow squash, asparagus stems, spinach leaves, and broccoli stems are all eaten with gusto. This diet can be supplemented with specialty "pleco" foods, but be wary. Many specialty pleco foods are based on animal proteins such as shrimp or fish meal and contain very little plant matter. Check the ingredients list closely! You might be surprised to find that your "pleco tablets" have the exact same ingredients and nutritional values as your "carnivore" pellets. Frozen and/or lives foods can be offered rarely as a treat.

Captive spawning
Ancistrus are often the first loricariid spawned by hobbyists and are recommended by most expert loricariid breeders as a key stepping stone before moving on to the more difficult species. A. sp. 3 and A. triradiatus are both good species for the budding pleco breeder to cut their teeth on as they will readily spawn under "average" aquarium conditions. Although Ancistrus spawnings sometimes happen in a community tank, a species tank is best if the aquarist has set spawning as a specific goal. First of all you need at least one male and one female, check out Mats Petersson's sexing Ancistrus FAQ entry on how to tell the difference between male and females.

While many aquarists have spawned Ancistrus pairs in tanks as small as ten gallons, a 20 gallon, or even larger, breeding tank is better. I personally prefer a bare tank bottom (with the bottom pane either painted or covered with cardboard) spawning tank or with a very fine layer of sand or gravel for ease of cleaning. The method of filtration is up to the aquarist, but any intakes to powered filtration devices must be covered with a sponge for the fry's safety. Lighting is optional, but if used, should not be too bright.

I prefer an arrangement of one male and one to two females depending on the breeding tank's size. In a breeding tank with more than one male, the males will sometimes spend so much time fighting over food, caves, and females that they never actually spawn with the female(s). The breeders should be of roughly the same size, or even better, the females larger than the male. A small female Ancistrus can be bullied nearly to death by a much larger amorous male.

The tank should contain one or more spawning tubes (see part 2). I have had Ancistrus species spawn in clay pots, coconut shells, and on pieces of driftwood and have seen others spawn them in everything from plastic boxes to gaudy aquarium castles. I even once saw a pair of A. sp. 3 simply spawn in the open in a corner of a dealer's display tank. I have noticed that, when given a choice, all Ancistrus species I have spawned prefer the PVC tubes I make. They also make things easier after the spawn as I will explain later. The remainder of the spawning tank can be decorated with one or more pieces of driftwood and an individual cave structure for each female.

A. sp. 3 and A. triradiatus will spawn under the same conditions. The tank's temperature should be kept between 76-80°F/24-27°C, the pH between 6.5 and 7.6.

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